Malaysia has decided to abandon a six-year experiment in using English in state schools to teach maths and ­science. The plan was intended to produce a new generation of global communicators, but government officials say it has stalled attainment and exposed a dearth of teachers able to deliver classes in English.

Education minister Muhyiddin Yassin announced last Wednesday that the English-medium education policy introduced across the country in 2003, known as PPSMI, would be phased out from 2012. He said that evidence gathered during a year-long assessment and public consultation had convinced the government that PPSMI wasn't working, and that the dominance of English in the curriculum risked undermining students' grasp of their first language.

"I wouldn't say it's a complete failure but it has not achieved the desired objectives that it was supposed to achieve," Muhyiddin told a press conference.

"The government is convinced that science and maths need to be taught in a language that will be easily understood by students, which is Bahasa Malay in national schools, Mandarin in Chinese schools and Tamil in Tamil schools."

But supporters of the policy ­expressed dismay, calling the decision a lost opportunity for Malaysia to emulate the economic success of English-speaking Singapore, held up as an example of how language skills can be a key to a connecting local workers and industries to the global economy.

The Parents Action Group for Education (Page), which had campaigned to maintain PPSMI, said the change would be unfair on many parents.

"There might be some schools which would want to continue teaching in English," Page chairman Azimah Abdul Rahim told the New Straits Times newspaper. "I think there should be a choice. There are many Malaysians whose first language is English."

The use of English for teaching in class has been a politically charged ­issue since it was decreed by Malaysia's autocratic prime minister, Dr Mahathir Mohamad, months before he stood down from office in 2003.

Since he was a staunch nationalist during his 22 years in power, Mahatir's move was a surprise acknowledgement that the post-independence policy he had championed of promoting Malay identity and downgrading the country's anglophone colonial past had been a mistake.

English-medium teaching was phased out of most schools by the 1970s. As a result the economy stagnated and Malaysia needed to develop a workforce skilled in the language of commerce and technology if it was to catch up with its south-east Asian competitors, he argued.

Many schools struggled from the start to deliver maths and science lessons in English, but the promise of future economic gains, and enthusiasm among parents, particularly in urban areas, for their children to acquire ­better English helped to maintain government commitment to the policy.

But in more recent years few have been able to ignore an emerging skills gap between urban and rural schools as education authorities outside the major cities failed to find enough staff able to teach in English. Meanwhile, government opponents have fanned nationalist fears by claiming that Malay culture was being undermined by PPSMI.

In 2008 the government responded to growing pressure by setting up a review of PPSMI, and an expert panel delivered its report to ministers in January, but a decision was stalled until after parliamentary elections in April.

In March police in Kuala Lumpur used teargas to disperse up to 5,000 ethnic Malays who took to the streets to voice their opposition to the policy.

In his statement, Muhyiddin denied that the government had bowed to political pressure, stressing instead that the decision had been taken on the basis of educational results alone.

He claimed these showed that the students who had been taught maths and science in ­English since they started primary school were now performing less well in those subjects in national exams than previous cohorts.

He said the percentage of students who achieved grade A to C for science had dropped by 2.5% in urban schools and 3% in rural schools. For maths, the results had fallen by around 4% in both urban and rural schools.

He added that only 8% of teachers were using English exclusively in classes while the use of Bahasa Malay was still common, particularly in rural areas, with on average just over half of PPSMI teaching time being delivered in English.

English-medium instruction will be phased out from schools from 2012 and the focus shifted to teaching ­English in separate language classes alongside improved Bahasa Malay teaching, Muhyiddin said.

He said that up to 14,000 English language teachers would be recruited by 2012, as well as specialist teaching assistants. English language teaching time will be increased by up to 30% a week, Muhyiddin added.

However, some critics were sceptical that qualified teaching staff can be found. "What has not occurred to the authorities is that the education system requires very competent teachers," Khoo Kay Kim, emeritus professor at the University of Malaya's history department, told the Reuters news agency.

Meanwhile, the still influential architect of PPSMI was quick to rally support for his policy. The octogenarian Dr Mahathir is using his popular blog to canvass opinion. "I am not surprised over the disappointment and even anger towards the government's decision ... Seems to me like the government is not listening to the voice of the people," he wrote.

Within hours of putting up his online poll, 40,000 people had ­responded with a resounding 84% opposed to the changes.